| Abstract Detail
Howard, Jamie H. [1], Farruggia, F. T. [2], Lipka, Carrie A. [3], Jones, Rodney B. [4], Obrock, Blake R. [4], Gutierrez, Raul [3], Wojciechowski, Martin F. [5]. Testing the Phylogenetic Value of Several Nuclear Molecular Markers Within Hologalegina (Fabaceae). Hologalegina (Fabaceae) is a large, diverse group of primarily temperate, herbaceous legumes. The group’s phylogenetic relationships are complicated by its size and recent diversification. While most legume phylogenies have relied heavily, if not exclusively, on plastid gene datasets, sequences of nuclear genes and gene-spanning regions offer certain advantages, given the generally faster evolutionary rates and their historical independence, i.e., non-linkage of most loci. For maximum utility, nuclear markers should be low- or single-copy to allow better assessment of orthology across diverse lineages. We decided to test the phylogenetic utility of several nuclear loci that included both coding and intron-spanning regions, each further classified as conserved or divergent, which had been identified through comparative genomic analyses as putative single-copy genes. The following molecular markers were used: PGDH (phosphogluconate dehydrogenase), a conserved exon; TRPT (triosephosphate translocator), a diverged exon; HRIP (similar to HR lesion-inducing ORF) and RNAR (ribonucleotide reductase), conserved intron-spanning sites; and, CNGC4 (CNG4-like protein), a diverged intron-spanning site. Twenty legume taxa within Hologalegina (plus a few outgroups) were used for the assessment. Each molecular marker was analyzed individually and as part of a concatenation of sequences using both parsimony and likelihood. These trees were then compared to trees based on plastid matK/trnK sequences from a much larger set of taxa to assess congruency. Preliminary results suggest that TRPT (within-genus pairwise distances in the 6-7% range; between genera distances in the 9-27% range) and CNGC4 (4-13% within genus; 3-19% between genera) are the most promising markers for Hologalegina phylogenetics. While the nuclear sequences evaluated in this study are relatively short (sizes ranged from 350 to 600bp), using a combination of at least two of these regions can provide a sufficient number of informative characters that fully resolve trees at the genus level and, in some cases, species levels in legumes.
Log in to add this item to your schedule
1 - Arizona State University, School of Life Sciences, P.O. Box 874601, Tempe, Arizona, 85287-4601, USA
2 - Arizona State University, School of Life Sciences, P.O. Box 874601, Tempe, Arizona, 85287, USA
3 - Arizona State University, School of Life Sciences, Tempe, Arizona, 85287, USA
4 - Arizona State University, School of Life Sciences, Tempe, AZ, 85287, USA
5 - Arizona State University, School of Life Sciences, P.O. Box 874501, Tempe, Arizona, 85287-4501, USA
Keywords:
Fabaceae
phylogenetics
nuclear genes
Hologalegina.
Presentation Type: Array
Session: TBA
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: 021
Abstract ID:1928 |
